From time to time, we find the beaches here in Chicago have a “swim advisory” or even have a posted status of “closed” on the Chicago Beaches website (http://www.cpdbeaches.com/home.cfm). And we find ourselves asking what does this really mean? Is it still safe to swim? What if I really need to get my open water workout in and today is the only day that works? Well we wanted to break it all down for you so that you can swim safe and avoid any illnesses (also known as the lake plague) that might set your training back.
What causes a swim advisory?
The Chicago Park District tests the water for Enterococci bacteria. Enterococci is not harmful itself and is naturally occurring the environment. However, this bacteria is an indicator of the presence of other pathogens that could make you sick. US Environmental Protection Agency (USEPA) beach policy recommends notifying the public when Enterococci bacteria levels are above the federal water quality Beach Action Value (BAV), which is 1000 CCEs (The unit of measuring DNA is "enterococci calibrator cell equivalents (CCE) per 100 milliliters of water). This standard is used at beaches throughout the Great Lakes region. For more information please refer to the USEPA Recreational Water Quality Criteria.
How do they test it?
The Chicago Park District and the University of Illinois at Chicago School of Public Health have partnered to expand the water quality testing program to utilize a new Rapid Testing method developed by the US Environmental Protection Agency (USEPA). The Rapid Testing method measures levels of bacterial DNA in beach water. The traditional Culture Based method provides results after 18-24 hours, but the Rapid Test provides results within 3-4 hours. The Chicago Park District can use results of the Rapid Test to notify the public when the risk is elevated for developing gastrointestinal symptoms.
Can I still swim?
You can but should you? When levels are elevated there is a good chance that there are other pathogens and bacteria that can make you sick...and we mean really sick! Because we don’t like to swim in dirty water, Live Grit cancels or postpones any open water swims in accordance with the park district’s recommendation. We don’t want you or our coaches getting sick! Typically the bacteria levels will change in 24-48 hours so be sure to check back in with the park district to see when it’s safe to swim.
With all of this information, you can now safely and efficiently check the water quality of Chicago beaches and make an informed decision on your ability to swim! Let us know if you have any questions.